1. Field of the Invention
The present invention is related to a fan frame device, particularly to a fan frame device of a cooling fan.
2. Brief Description of Related Art
Due to electronic products progressing rapidly, the running speeds of various electronic components in the electronic products are getting faster and data access rates thereof are getting increasing so that more heat is generated and it results in high temperature being kept in the electronic components. The computer is a typical one of the electronic products.
Originally, the main unit of a computer was designed without heat dissipation device except the cooling device attached to the power supplier helping to perform heat dissipation of the main unit. The heat dissipation has become an important factor for keeping running steadily in the recent year. Currently, the most popular heat dissipation device is fan and radiator, which carry out the heat dissipation job by way of convection and conduction.
The preceding radiator usually is made of aluminum alloy or copper and conductivity is a criterion to determine a good or bad radiator. Further, amount of the area contacting with flowing air is an essential factor influencing effect of heat dissipation. Hence, the more the surface area of the radiator contacts with the air, the better the effect of heat dissipation can be obtained.
The preceding fan provides a function of forcing cooling air passing over the surface of the radiator so that the faster the rotational speed of the fan is, the better the effect of heat dissipation is.
Therefore, computer components capable of generating a great deal of heat are designed with a function of heat dissipation. It requires the radiator only in case of the computer components generating less heat and it required the radiator associated with the fan in case of the computer components generating more heat. For instance, the chip module usually is attached with a radiator and the central processing unit (CPU) and graphic processing unit (GPU) on 3D accelerating card are attached with a radiator associated with a fan respectively.
In order to guarantee the CPU and the GPU operating safely and reliably, the method popularly used is to increase effective discharge power of the fan and the rotational speed of the fan respectively.
Further, referring to FIGS. 1 to 3, a conventional fan comprises a fan frame 11 and a fan wheel 12. The fan frame 11 provides a hollow case with a frame wall 111 and a flow passage 115 is defined with an inlet 112 and an outlet 113 being disposed at two lateral sides of the fan frame 11. A hub seat 114 is disposed in the flow passage 115 and the fan wheel 12 comprises a hub 121 and a plurality of fan blades 122 extending outward from the hub 121 in a radial direction. Then, the fan wheel 12 is movably attached to the hub seat 114. When the fan wheel 12 rotates, the fan blades 122 drags fluid to flow into the flow passage 115 via the inlet 112 from the fan frame 11 and flow out via the outlet 113.
However, a problem of the conventional fan in practice is in that the area of the inlet 112 available for the incoming fluid has been defined by the frame wall 111 so that only limited amount of fluid can be dragged by the fan and the radial pressure of fluid impacts the frame wall 111 to produce noise during the fluid moving into the flow passage 115.